criba: who is calling your MCP server

by cribalo Your server? Claim it

answering

criba: who is calling your MCP server is answering right now. Last checked 15 min ago. It exposes 3 tools.

Identify who calls your MCP server or A2A agent: declared identity vs observed behaviour.

Uptime history 33 hours of history

33 hours agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

251 ms

Response time

average over 24h

open, no key

Access

streamable-http

Nothing serious here today

Today is the operative word: we check criba: who is calling your MCP server every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 15 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add criba --transport http https://criba.cribalo.com/mcp

Settings → Connectors → Add custom connector, then paste this address

https://criba.cribalo.com/mcp

~/.codex/config.toml

[mcp_servers.criba]
url = "https://criba.cribalo.com/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "criba": {
      "url": "https://criba.cribalo.com/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "criba": {
      "type": "http",
      "url": "https://criba.cribalo.com/mcp"
    }
  }
}

Available tools 3

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

classify

classify_visitor

Classify one visitor from its requests to your MCP server, A2A agent or website. Returns the declared identity, the observed behaviour class (acts-on-results, agent-tool-use, agent-message, probe, indexer, web-scanner, web), the signals and reasons, and mismatch=true when behaviour contradicts the declared identity. All event fields are optional; send what your server parsed. At most 500 events.

identify

identify_client

Who a User-Agent and/or an MCP clientInfo.name claims to be, matched against criba's catalog of known MCP indexers, verifiers, A2A directories, AI crawlers, scanners and HTTP libraries. This is a declaration, not proof: use classify_visitor for behaviour. Pass at least one of the two.

known

list_known_bots

List criba's catalog of known agent-ecosystem bots, optionally filtered by category or protocol. Each entry has its id, name, category, URL, matching rules and what it was seen doing. Catalog 2026-11-08, CC-BY-NC-4.0 (non-commercial use with attribution).

Endpoints

URL	Transport	State	Latency	Checked
https://criba.cribalo.com/mcp	streamable-http	answering	232 ms	15 min ago

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7 tools answering

criba: who is calling your MCP server — questions

Answers built from our own checks of this server.

What can criba: who is calling your MCP server do?

It exposes 3 tools, read directly from the server on our last check. Among them: classify_visitor, identify_client, list_known_bots. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is criba: who is calling your MCP server working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 251 ms. The bar chart above shows every period we have measured.

How do I connect criba: who is calling your MCP server?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does criba: who is calling your MCP server need an API key?

No. criba: who is calling your MCP server completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 3 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is criba: who is calling your MCP server?

It answers our handshake in 251 ms on average, which is faster than 54% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.